Monoazo dyestuffs and their metal complex compounds



United States Patent MONOAZO DYESTUFFS AND THEIR METAL COMPLEX COMPOUNDSAlfons Dorlars, Leverkusen-Schlebusch, and Otto Bayer and Edgar Enders,Leverkusen-Bayerwerk, Germany, assignors to. Farbenfabrikeri BayerAktier'l'ges'ellschatt, Leverkusen, Germany, a corporation of Germany NoDrawing. Application May 3, 1955,

Serial N0. 505,838

Claims priority, application Germany May 8, 1954 7 Claims. (CL 260-446)The present invention relates to monoazo dyestuffs, their metal complexcompounds and to methods of making the same; more particularly itrelates to monoazo dyestuffs corresponding to the following formula:

in this formula R stands for a radical of the benezene series being freefrom sulfonic and carboxylic acid groups and bearing the hydroxy groupin o-position to the -N=N-bridge. The invention further relates to metalcomplex compounds of these mo'n'oaZo dyestuffs.

The new monoazo dyestufis can be obtained by coupling the diazocompounds of o-hydroxy aminobenzenes with components of the following.formula:

o oorn which couple in o-position to the hydroxy group.

The monoazo dystuffs thus obtained can be converted into their metalcomplex compounds by a treatment with metal yielding agents in usualmanner either on the fibre or in the dye bath or in substance. Thedyestuffs are e. g. well suited for the monochrome process.

The conversion of the new dyestutfs in their metal complex compounds,preferably into their chromium complex compounds, may be carried out inadmixture with other metallizable monoazo dyestuffs.

The manufacture of metal containing d'yestuifs in substance takes placein the usual manner, e. g. in the absence or presence of complex formingcompounds such as oxalic acid, salicylic acid, etc.

Suitable diazo compounds for the production of the new dyestuffs are e.g. l-amino-2-hydroxy-5-chlorobenzene,1-amino-2'-hydroxy-3,5-dichlorobenzene, 1-amino-2-hydroxy--nitrobenzene, 1 amino-2-"hydroxy-3-chloro-5- nitrobenzene, 1amino-Z-hydroxy-3-nitrobenzene-S-sulfonamide, 1amino-2-hydroXy-3-nitrobenZene-S-methylsulfone, etc.

The 1 hydroxy 2 [pyrrolidonyl( l")"]-4 alkylbenzenes, used as couplingcomponents inthe present process may contain straight-chained, branchedor cyclic alkyl groups with 1 to 8 carbon atomsr They are obtained bythe reaction of 1-hydroxy-2-amino-4 alkylbenzenes with 'ybutyrolactone,as described in Berichte der Deutschen Chemischen Gesellschaf 69, page2727.

The coupling process is carried out in water or organic ice solvents asdimethyl torrnamide, in the presence of acid binding materials as sodalye, ammonia, soda, milkof lime, magnesium carbonate or pyridine.

The new monoazo dyestuffs yield on wool, afterchromed, brownish-red tobrown dyeings of very good fastness to light and good fastness to wearand tear and good fastness to processing.

The dyestuffs metallized in substance dye wool and silk as well aswool-like synthetic fibres from superpolyamides, superpolyurethanes andcasein fibres as well as leather from neutral or weakly acid bath; theypossess excellent leveling and penetrating properties. In theseproperties they exceed other comparable known dyestuifs, which containinstead of the pyrrolidine group e. g. a'n acetylarnino group. Thedyeings thus obtained possess a very good fastness to light and goodfastness to wear and tear and to processing.

The new monoazo dyestuffs which are chromed in admixture with othermonoazo dyestufis show similar general and fastness properties.

The following examples illustrate the invention, without, however,limiting it thereto; the parts being by weight:

Example 1 15.4 parts of 1-amino-2-hydroxy-5-nitrobenzene are indirectlydiazotized in usual manner and the formed diazo compound salted out andfiltered with suction. The separated diazo compound is gradually addedwith stirring to a solution of 192 parts of 1-hydroxy-2-(N-pyrrolidonyl)-4-methylbenzene, 4 parts of sodium hydroxide in 350 parts ofpyridine and 40 parts of water which is cooled to a temperature of -10C. to -5 C. After coupling is finished the pyridine is distilled oil invacuo and the formed monoazo dyestufl corresponding to the followinggeneral formula:

0 OH HO /C-CH2 N=N N\ l CHrCH:

N02 CH2 is purified by dissolving it in water and salting out. A blackpowder is obtained which dyes wool by the monochrome process inreddish-brown shades.

Example 2 35.6 parts of the monoazo dyestutf, described in Example 1,are dissolved in 350 parts of hot water and 40 parts of 10 per cent sodasolution. 200 parts of an chromium-ammonium-'oxalate solution whichcorresponds to 26 parts of chrome per litre, are d'ropwise added to thesolution of the monoazo dyestuif with stirring at a temperature of -100C. When the reaction is finished the chrome containingmonoazo dyestufiis filtered with suction and dried. It represents a black powder whichdyes wool from a neutral or weakly acid bath in reddishbrown shades ofgood fastness properties.

A chromium complex dyestuif of similar properties is obtained, if asolution of 7.9 parts of sodium bichromate and 6 parts of 40 percentsodium hydroxide in 30 parts of water together with asolution of 10parts of commercial glucose in- 40 parts of water is added dropwise withstirring. to a solution of 35:6 partsof the aforesaid dyestutf in 250parts of water and 12 parts of- 40 percent sodium hydroxide at atemperature of 95 C.

Example 3 23.3 parts of l-amino-2-hydroxy-3-nitrobenzene-5-sulfonamideare diazotized with 6.9 parts of sodium nitrite in usual manner andcombined with 19.2 parts of 1- hydroxy 2(N-pyrrolidonyl)-4-methylbenzene as described in Example 1. Afterdistilling off the pyridine the dyestuif is redissolved from water. Amonoazo dyestulf of the following formula is obtained:

It represents a black-brown powder which dyes wool by the monochromeprocess in reddish dark-brown shades of good fastness to light and goodfastness to wet-treatment.

Example 4 15.4 parts of 1-amino-2-hydroxy-5-nitrobenzene are diazotizedas described in Example 1. The separated diazo compound is added to asolution of 23.3 parts of1-hydroxy-2-(N-pyrrolidonyl)-4-tertiary-butyl-benzene, 4 parts of sodiumhydroxide and 8 parts of soda in 350 parts of pyridine and 50 parts ofWater. The further process is the same as described in Example 1. Thedyeand forms, after drying, a dark powder which dyes wool by themonochrome process in dark red-brown shades of excellent fastnessproperties.

If the dyestuif is chromed as described in Example 2, a chrome complexmonoazo dyestuif is obtained which dyes wool from a neutral bath inlevel red-brown shades of good fastness to light and very good fastnessto wettreatment.

The l hydroxy 2-(N-pyrrolidonyl)-4-tertiary-butylbenzene can be obtainedby reacting l-hydroxy-Z-amino- 4-tertiary-butyl-benzene with'y-butyrolactone at a temperature of about 250 C. It forms colorlessneedles melting at 151 C.

We claim:

1. Dyestuffs selected from the group consisting of monoazo dyestuffscorresponding to the general formula wherein R stands for a radical ofthe benzene series being free from sulfonic and carboxylic acid groupsand bearing the hydroxy group in o-position to the N=N-bridge and R1 isan alkyl group having 1-8 carbon atoms and the chromium complexcompounds thereof.

2. Dyestuffs selected from the group consisting of monoazo dyestuffscorresponding to the general formula wherein R stands for a radical ofthe benzene series being free from sulfonic and carboxylic acid groupsand hearing the hydroxy group in o-position to the --N=N-bridge and thechromium complex compounds thereof.

3. A dyestuff selected from the group consisting of a monoazo dyestutfcorresponding to the formula i C CH2 and the chromium ICOITIPIEZXcompound thereof.

4. A dyestutf selected from the group consisting of the monoazo dyestuifcorresponding to the formula:

OH HO I /CCH2 02N- N N CHz-OHz SOzNH7 H3 and the chromium complexthereof.

5. A dyestutf selected from the group consisting of a monoazo dyestuifcorresponding to the formula OH HO /CCH2 Cl- N=N N I CHPCHQ CHa and thechromium complex compound thereof.

6. A dyestulf selected from the group consisting of a monoazo dyestuffcorresponding to the formula and the chromium complex compound thereof.

7. A dyestufi selected from the group consisting of a monoazo dyestutfcorresponding to the formula 0 OH HO ([L CH2 Ol- N=N N\ I CH2CH N02 CH:

and the chromium complex compound thereof.

[No references cited.

1. DYESTUFFS SELECTED FROM THE GROUP CONSISTING OF MONOAZO DYESTUFFSCORRESPONDING TO THE GENERAL FORMULA